Elastic magnetoelectric flexible polishing tool head and use method

Abstract

The present invention relates to an elastic magnetoelectric flexible polishing tool head and a method of using the same, and belongs to the field of ultra-precision polishing. The elastic magnetoelectric flexible polishing tool head comprises a tool grinding head base and a grinding head, and the grinding head comprises a silicone rubber layer and a polytetrafluoroethylene layer; the polytetrafluoroethylene layer is bonded to the tool grinding head base, and a negative charge is provided on the surface of the polytetrafluoroethylene layer by deposition; the rubber layer is a solid mixture formed by mixing and consolidating liquid silicone rubber and iron powder particles, and the silicone rubber layer is bonded to the polytetrafluoroethylene layer. When in use, an external electric field is applied, and the charge moves back and forth between the polytetrafluoroethylene layer and the silicone rubber layer, driving the iron powder particles to move and causing the silicone rubber layer to deform. By adjusting the size of the electric field, the size of the magnetic field around the grinding head is adjusted to control the deformation, so as to adapt to the polishing of different complex and special-shaped surfaces, so as to achieve the effect of removing the intermediate frequency error remaining in the surface processing, thereby realizing a truly adaptive polishing technology, effectively improving the surface shape accuracy, and at a low cost.

Description

Technical Field

[0001] The invention belongs to the field of ultra-precision polishing, and in particular relates to an elastic magnetoelectric flexible polishing tool head and a use method thereof. Background Art

[0002] With the continuous development of optical surfaces, military industry, aerospace and other fields, the demand for complex surfaces is increasing. Complex surfaces are usually composed of a variety of surfaces with different curvatures, including aspherical surfaces, complex special-shaped surfaces and free-form surfaces. Compared with traditional optical flat elements and optical spherical elements, free-form surfaces with high precision and complex special-shaped surfaces have more advantages and are more suitable for major R&D projects. They are an important symbol of the level of manufacturing industry.

[0003] Polishing is the last step in the surface treatment of complex optical surfaces. It can effectively reduce the surface roughness of complex optical surfaces, improve surface accuracy and extend the service life of optical surfaces. Therefore, the polishing process has an indispensable influence on optical surfaces. The choice of polishing tool head directly determines the quality of the polishing effect to a certain extent.

[0004] At present, most of the polishing tool heads available on the market are airbag polishing tool heads. For example, the Chinese invention patent application with application publication number CN117161967A discloses an airbag polishing tool designed based on the negative pressure principle, including a semi-flexible spherical cap airbag shell, an airbag tool head handle, a negative pressure mechanism and a rubber tube. The negative pressure mechanism includes an external shell and a pneumatic negative pressure component. The external shell is installed at the bottom of the airbag tool head handle and is wrapped by the semi-flexible spherical cap airbag shell. The pneumatic negative pressure component is connected to the air supply hole through an air supply channel. When the air flow enters the pneumatic negative pressure component, a negative pressure area is generated at the bottom of the pneumatic negative pressure component; compressed air enters the pneumatic negative pressure component through the air supply hole and the air supply channel in turn, drives the pneumatic negative pressure component, and uses the rubber tube to form a negative pressure area between the semi-flexible spherical cap airbag shell and the polishing contact area of ​​the workpiece. When the negative pressure area is formed and the external air enters the micropores on the surface of the airbag, the auxiliary polishing liquid enters the polishing.

[0005] The above-mentioned airbag polishing tool heads are mostly bonded with glue and ventilated internally, which not only has a complex structural design, but is also affected by the internal air pressure and cannot achieve accurate and complete fit to the surface of complex optical curves. Summary of the invention

[0006] The purpose of the present invention is to provide an elastic magnetoelectric flexible polishing tool head and a method of use, so as to solve the problem that the existing polishing method cannot achieve accurate and complete fit to the surface of complex optical curved surfaces.

[0007] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0008] The invention relates to an elastic magnetoelectric flexible polishing tool head, which comprises a tool grinding head base and a grinding head, wherein the grinding head comprises a silicone rubber layer and a polytetrafluoroethylene layer; the polytetrafluoroethylene layer is bonded to the tool grinding head base, and a negative charge is provided on the surface of the polytetrafluoroethylene layer by deposition; the silicone rubber layer is a solid mixture formed by mixing and consolidating liquid silicone rubber and iron powder particles, and the silicone rubber layer is bonded to the polytetrafluoroethylene layer.

[0009] Preferably, the Shore hardness of the liquid silicone rubber is 10-80. A , viscosity is 3000~15000cps, and the thickness of the silicone rubber layer is 1mm~10mm.

[0010] Preferably, the particle size of the iron powder is 0.1 to 1 μm .

[0011] Preferably, the silicone rubber layer is formed by the following method: liquid silicone rubber and iron powder particles are poured into a beaker at the same time, stirred evenly, and then poured into a fixed mold, and formed by heating or natural consolidation.

[0012] Preferably, the negative charge is deposited on the polytetrafluoroethylene layer by:

[0013] A polytetrafluoroethylene layer is placed on a grounded surface, and a conductive needle and a grid electrode are placed on top of it. The conductive needle and the grid electrode are connected to different high-voltage power supplies respectively, so that the air between the conductive needle and the grid electrode is instantly ionized, accelerating the movement of charges to the polytetrafluoroethylene film, thereby achieving negative charge deposition on the surface of the polytetrafluoroethylene layer.

[0014] Preferably, the polytetrafluoroethylene layer is bonded to the tool grinding head substrate by silver glue, and the silicone rubber layer is bonded to the polytetrafluoroethylene layer by silver glue.

[0015] Preferably, the tool grinding head base comprises a stainless steel round rod at the bottom and a disc at the top, and the polytetrafluoroethylene layer and the silicone rubber layer are sequentially bonded to the disc.

[0016] Preferably, the stainless steel round rod has a diameter of 10 mm and a length of 60 mm; the disc has a diameter of 14 mm.

[0017] The present invention also relates to a method for using the elastic magnetoelectric flexible polishing tool head, which comprises the following steps:

[0018] S1. Place the elastic magnetoelectric flexible polishing tool head into the conductive coil, turn on the power to generate a magnetic field around the grinding head, accelerate the charge movement between the silicone rubber layer and the polytetrafluoroethylene layer, and deform the silicone rubber layer;

[0019] S2. According to the processing requirements of the complex and special-shaped surfaces of the workpiece, the electric field size is adjusted to change the magnetic field size around the grinding head, change the deformation of the silicone rubber layer, and then regulate the downward pressure of the grinding head at different processing points.

[0020] Preferably, the step of adjusting the magnitude of the S2 electric field comprises:

[0021] S2.1. Calculate the deformation of the silicone rubber layer according to the processing requirements of the complex and irregular curved surface of the workpiece. The calculation formula is:

[0022] ,

[0023] In the formula, △L is the deformation of the silicone rubber layer, △Z d is the difference between the actual surface shape and the theoretical surface shape, k is the proportionality coefficient;

[0024] S2.2. According to the calculated deformation of the silicone rubber layer, the current in the conductive coil is adjusted, and then the electric field is adjusted. The relationship between the deformation of the silicone rubber layer and the current in the conductive coil is:

[0025] ,

[0026] In the formula, △L is the deformation of the silicone rubber layer, μ 0 is the vacuum permeability, N is the number of turns of the energized coil, I is the current in the coil, L 0 is the initial height of the silicone rubber layer, R is the tool head radius, Y is the Young's modulus of the silicone rubber layer material.

[0027] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0028] 1. The grinding head of the elastic magnetoelectric flexible polishing tool head involved in the present invention includes a silicone rubber layer and a polytetrafluoroethylene layer. The surface of the polytetrafluoroethylene layer is provided with negative charges by deposition. The silicone rubber layer is a solid mixture formed by mixing and consolidating liquid silicone rubber and iron powder particles. When in use, an external electric field is applied, and the charges move back and forth between the polytetrafluoroethylene layer and the silicone rubber layer, thereby driving the iron powder particles to move and cause the silicone rubber layer to deform. Therefore, the size of the magnetic field around the grinding head can be controlled by adjusting the size of the electric field, thereby controlling the deformation of the tool grinding head to adapt to the polishing of different complex and special-shaped surfaces, thereby achieving the effect of removing the intermediate frequency error remaining from the surface processing, thereby realizing a truly adaptive polishing technology and effectively improving the surface shape accuracy.

[0029] 2. The grinding head of the elastic magnetoelectric flexible polishing tool head involved in the present invention includes a polytetrafluoroethylene layer with negative charges deposited on the surface and a silicone rubber layer mixed with iron powder particles. During the manufacturing process, negative charges are set on the polytetrafluoroethylene layer by deposition, and then the polytetrafluoroethylene layer is bonded to the tool grinding head base with silver glue. Finally, the silicone rubber layer mixed with iron powder particles is bonded to the polytetrafluoroethylene layer with silver glue. The manufacturing method is simple and the cost is low.

[0030] 3. The silicone rubber layer of the elastic magnetoelectric flexible polishing tool head of the present invention is a solid mixture formed by mixing and consolidating liquid silicone rubber and iron powder particles. The polishing tool head of different shapes can be customized as needed, and has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a front view of the elastic magneto-electric flexible polishing tool head;

[0032] Figure 2 It is an exploded view of the elastic magneto-electric flexible polishing tool head;

[0033] Figure 3 is a schematic diagram of the charge deposition process of the polytetrafluoroethylene layer;

[0034] Figure 4 Schematic diagram of the surface shape of the polishing tool head being changed by applying an electric field;

[0035] Figure 5 It is a schematic diagram of the time-space controlled processing of the elastic magneto-electric flexible polishing tool head during polishing.

[0036] Among them, 1-tool grinding head base, 11-stainless steel round rod, 12-disc, 2-grinding head, 21-polytetrafluoroethylene layer, 22-silicone rubber layer, 23-negative charge, 3-conductive needle, 4-grid electrode, 5-high voltage power supply, 6-conductive coil, 7-power supply. DETAILED DESCRIPTION

[0037] The technical scheme of the present invention is further specifically described below through specific embodiments. The embodiments are for the purpose of explaining the present invention, not for limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] See attached Figure 1 and 2As shown, the elastic magnetoelectric flexible polishing tool head of the present invention comprises a tool grinding head base 1 and a grinding head 2, wherein the tool grinding head base 1 comprises a stainless steel round rod 11 at the bottom and a disc 12 at the top, wherein the stainless steel round rod 11 has a diameter of 10 mm and a length of 60 mm; the disc 12 has a diameter of 14 mm, and the grinding head 2 comprises a silicone rubber layer 22 and a polytetrafluoroethylene layer 21.

[0039] The polytetrafluoroethylene layer 21 is formed on the disc of the tool grinding head substrate 1 by silver glue. The polytetrafluoroethylene layer 21 is a polytetrafluoroethylene film, and a negative charge 23 is provided on its surface by deposition. The polytetrafluoroethylene film is selected because the polytetrafluoroethylene film hardly deforms in a magnetic field, and polytetrafluoroethylene is a good net negative charge 23 carrier. The negative charge 23 can be deposited on the surface of polytetrafluoroethylene for a long time, so after the electric field and magnetic field are involved, the charge can move freely; and due to the corrosion resistance of polytetrafluoroethylene, the polishing head 2 can be prevented from being corroded by the polishing liquid with acidity and alkalinity during the polishing process, thereby enhancing the durability of the polishing head 2. Refer to the attached Figure 3 As shown, when negative charges 23 are deposited on the polytetrafluoroethylene layer 21, the polytetrafluoroethylene layer 21 is placed on a grounded surface, and a conductive needle 3 and a grid electrode 4 are placed on the top, respectively. The conductive needle 3 and the grid electrode 4 are respectively connected to different high-voltage power supplies 5, so that the air between the conductive needle 3 and the grid electrode 4 is instantly ionized, accelerating the movement of charges to the polytetrafluoroethylene film, thereby realizing the deposition of negative charges 23 on the surface of the polytetrafluoroethylene layer 21.

[0040] The silicone rubber layer is a solid mixture of liquid silicone rubber and iron powder particles, and the Shore hardness of the liquid silicone rubber is 10-80. A , viscosity is 3000~15000cps, hardness and magnetism can be controlled by adjusting the ratio of silicone rubber to iron powder particles; the thickness of the silicone rubber layer is 1mm~10mm, and the thickness of the rubber can be determined according to the material and hardness of the workpiece to be processed. The silicone rubber layer is formed by the following method: pour liquid silicone rubber and iron powder particles into a beaker at the same time, stir evenly and pour into a fixed mold, and heat or naturally solidify to form. The particle size of the iron powder is 0.1~1 μm The silicone rubber layer 22 is placed on the polytetrafluoroethylene layer 21 through silver glue.

[0041] The method for using the elastic magnetic and electric flexible polishing tool head comprises the following steps:

[0042] S1. Refer to the attached Figure 4 As shown, the elastic magnetoelectric flexible polishing tool head is placed in the conductive coil 6, and the power supply 7 is turned on to generate a magnetic field around the grinding head 2, which accelerates the charge movement between the silicone rubber layer 22 and the polytetrafluoroethylene layer 21, causing the silicone rubber layer 22 to deform;

[0043] S2. According to the processing requirements of the complex and irregular curved surface of the workpiece, the electric field is adjusted to change the magnetic field around the grinding head, change the deformation of the silicone rubber layer 22, and then adjust the downward pressure of the grinding head at different processing points to complete the polishing of the workpiece. Figure 5 As shown in the figure, when polishing the workpiece surface, due to the uneven surface of the workpiece, relative to the theoretical processing surface, the actual workpiece has protrusions in some places and pits in some places. Before polishing, the depth of different protrusions or pits is obtained by measuring the surface morphology of the workpiece to guide the change of the pressure. The change of the pressure is the deformation of the silicone rubber layer. The calculation formula is:

[0044] ,

[0045] In the formula, △L is the deformation of the silicone rubber layer, △Z d It is the difference between the actual surface shape and the theoretical surface shape obtained when measuring the surface morphology of the workpiece. k is the proportionality factor, k Can be self-defined according to the removal rate of the polishing tool head;

[0046] During polishing, the amount of pressure applied by the tool head needs to be increased for the raised areas, and decreased for the areas with pits. Specifically, the deformation of the silicone layer 22 is changed by regulating the magnetic field. When the electric field increases, the movement of the negative charge 23 between the silicone rubber layer 22 and the polytetrafluoroethylene layer 21 is accelerated, thereby causing the iron powder particles in the silicone rubber layer 22 to move, thereby changing the shape of the grinding head 2. The larger the electric field, the greater the deformation, and the corresponding pressure increases accordingly; conversely, the smaller the electric field, the smaller the deformation, and the corresponding pressure decreases accordingly. In this way, the amount of pressure is regulated to perform polishing regulation on the raised areas on different surfaces. The regulation of the electric field can be achieved by adjusting the current in the conductive coil. The relationship between the deformation of the silicone rubber layer and the current in the conductive coil is:

[0047] ,

[0048] In the formula, △L is the deformation of the silicone rubber layer, μ 0 is the vacuum permeability, N is the number of turns of the energized coil, I is the current in the coil, L 0 is the initial height of the silicone rubber layer, R is the tool head radius, Y is the Young's modulus of the silicone rubber layer material.

[0049] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An elastic magnetoelectric flexible polishing tool head, characterized in that: It includes a tool grinding head base and a grinding head, the grinding head includes a silicone rubber layer and a polytetrafluoroethylene layer; the polytetrafluoroethylene layer is bonded to the tool grinding head base, and a negative charge is set on the surface of the polytetrafluoroethylene layer by deposition; the silicone rubber layer is a solid mixture formed by mixing and consolidating liquid silicone rubber and iron powder particles, and the silicone rubber layer is bonded on the polytetrafluoroethylene layer; the negative charge is deposited on the polytetrafluoroethylene layer by the following method: A polytetrafluoroethylene layer is placed on a grounded surface, and a conductive needle and a grid electrode are placed on top of it. The conductive needle and the grid electrode are connected to different high-voltage power supplies respectively, so that the air between the conductive needle and the grid electrode is instantly ionized, accelerating the movement of charges to the polytetrafluoroethylene film, thereby achieving negative charge deposition on the surface of the polytetrafluoroethylene layer.

2. The elastic magnetic electric flexible polishing tool head according to claim 1, characterized in that: The Shore hardness of the liquid silicone rubber is 10-80 A , viscosity is 3000~15000cps, and the thickness of the silicone rubber layer is 1mm~10mm.

3. The elastic magnetic electric flexible polishing tool head according to claim 1, characterized in that: The particle size of the iron powder is 0.1~1 μm .

4. The elastic magnetic electric flexible polishing tool head according to claim 1, characterized in that: The silicone rubber layer is formed by the following method: liquid silicone rubber and iron powder particles are poured into a beaker at the same time, stirred evenly, poured into a fixed mold, and formed by heating or natural consolidation.

5. The elastic magnetic electric flexible polishing tool head according to claim 1, characterized in that: The polytetrafluoroethylene layer is bonded to the tool grinding head substrate through silver glue, and the silicone rubber layer is bonded to the polytetrafluoroethylene layer through silver glue.

6. The elastic magnetic electric flexible polishing tool head according to claim 1, characterized in that: The tool grinding head base comprises a stainless steel round rod at the bottom and a disc at the top, and the polytetrafluoroethylene layer and the silicone rubber layer are sequentially bonded on the disc.

7. The elastic magnetic electric flexible polishing tool head according to claim 6, characterized in that: The diameter of the stainless steel round rod is 10 mm and the length is 60 mm; the diameter of the disc is 14 mm.

8. A method for using the elastic magnetic electric flexible polishing tool head according to claim 1, characterized in that: It includes the following steps: S1. Place the elastic magnetoelectric flexible polishing tool head into the conductive coil, turn on the power to generate a magnetic field around the grinding head, accelerate the charge movement between the silicone rubber layer and the polytetrafluoroethylene layer, and deform the silicone rubber layer; S2. According to the processing requirements of the complex and special-shaped surfaces of the workpiece, the electric field size is adjusted to change the magnetic field size around the grinding head, change the deformation of the silicone rubber layer, and then regulate the downward pressure of the grinding head at different processing points.

9. The method for using the elastic magnetic electric flexible polishing tool head according to claim 8, characterized in that: The step of adjusting the magnitude of the S2 electric field comprises: S2.

1. Calculate the deformation of the silicone rubber layer according to the processing requirements of the complex and irregular curved surface of the workpiece. The calculation formula is: ， In the formula, △L is the deformation of the silicone rubber layer, △Z d is the difference between the actual surface shape and the theoretical surface shape, k is the proportionality coefficient; S2.

2. According to the calculated deformation of the silicone rubber layer, the current in the conductive coil is adjusted, and then the electric field is adjusted. The relationship between the deformation of the silicone rubber layer and the current in the conductive coil is: ， In the formula, △L is the deformation of the silicone rubber layer, μ 0 is the vacuum permeability, N is the number of turns of the energized coil, I is the current in the coil, L 0 is the initial height of the silicone rubber layer, R is the tool head radius, Y is the Young's modulus of the silicone rubber layer material.

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